This invention relates to a grafting method and apparatus for uniting a lower end portion of a scion to an upper end portion of a stock.
Grafting is a plant growing method which produces a new individual plant by uniting a scion having the affinity relative to a stock to the stock in order to improve the acclimation, noxious insect-resistant, flowerability, and fructifiability. In grafting, there have been splice, saddle, and cleft grafting methods, etc.
For example, as shown in FIG. 17, in the cleft grafting method, a lower end portion of a scion 351 is cut up into a wedge-like form by the use of a knife or the like and a corresponding wedge-like slit 353 is formed at an upper end portion of a stock 352. After the lower end portion of the scion 351 is inserted into the slit 353 to unite the vascular bundles of the scion 351 and the stock 352, the united portion is gripped by an auxiliary fixing device such as a clip.
This cleft grafting method of inserting the lower end portion of the scion 351 cut up into -the wedge-like form into the slit 353 of the stock 352 has suffered the following problems: 1) a skill is required to unite the scion 351 to the stock 352 in a proper state: and 2) it is difficult to automate the grafting operation. More specifically, uniting surfaces of the scion 351 and the stock 352 consist of a pair of flat surfaces each, and only parts of vessels 354 and sieve tubes 355 constituting the vascular bundles are exposed at opposite uniting surfaces. Accordingly, it is difficult to position and unite the vessels 354 and sieve tubes 355 of the scion 351 to those of the stock 352 accurately. This has stood as a hindrance to the automation. In addition, it has been difficult to automate an operation of attaching the auxiliary fixing device to the united portion of tbe scion 351 and stock 352 and an operation of detaching the auxiliary fixing device after the uniting portion is connected fast.
Also, it has been very difficult to cut the seedling by means of the razor blade or the like into a proper shape without destroying its tissue having an anisotropic fibroid structure, which accordingly hinders automation of grafting operation. More specifically, to cut the scion 351 into a desired shape while holding a stem of the scion 351 by the holding member, it is necessary to give an appropriate intensity of cutting energy to the razor blade. Unless the necessary cutting energy is given to the cutting blade, the cut surface of the scion 351 will not be finished into the proper cutting surface. On the contrary, if an exceeding cutting energy is applied, the portion of stem of the scion 351 where the holding member holds will be liable to be damaged.
Further, since a cuticle of the scion 351 remains on a portion other than the cut surfaces, roots may come out from the remaining cuticle after the adhesion. This prevents the growth of the stock 352, thereby reducing the growth and thickening of the stock 352, i.e. causing a so-called stock undergrowing phenomenon. Furthermore, the cleft grafting method also suffers the problem that the stock 352 splits as the roots of the scion 351 grow.
In view thereof, it is an object of the invention to provide a grafting method and apparatus which have overcome the above-mentioned drawbacks.
It is another object of the invention to provide a grafting method and apparatus which make it possible to unite a scion to a stock in a proper state without causing the rooting of the scion and the undergrowth of the stock.
It is still another object of the invention to provide a grafting method and apparatus which enable automatic grafting.
It is yet still another object of the invention to provide a grafting method and apparatus which assure easy and accurate cutting of scions and stocks.